Ecology surveys are commonly used during proposed site developments for assessing the potential environmental impact and to ensure natural habitats and protected species are not harmed or disturbed as part of the development process. While this method of surveying is effective, it can present challenges in providing accurate data in relation to which species live where as well as their numbers.
Environmental DNA or eDNA is a recent development in this field that could significantly improve the way wildlife is monitored. This article will look in more detail at eDNA survey methodology as well as some of the differences between eDNA surveys and field surveying.
What Is Environmental DNA (eDNA)?
This survey technique involves analysing DNA shed from organisms and found in their habitats rather than directly from the species themselves. DNA samples are commonly taken from sources such as hair, skin, faeces and mucous found in water.
Currently, eDNA surveys are used to confirm the presence of bat species, as well as the great crested newt, though there are plans to expand the scope of this methodology to more species such as aquatic organisms.
eDNA Survey Protocol
eDNA surveys can only be conducted during certain time frames which are between 15 April and 30 June. Water samples are taken by an ecologist using eDNA test kits which include a mixing bag, sterilised pipette, sampler, preserving fluid tubes and a pair of gloves.
Once the sample is taken it is sent to a laboratory where it is analysed using DNA sequencing methods for a fast and efficient method of monitoring and measuring biodiversity. The results are usually returned within two weeks.
eDNA vs Field Surveying
Some of the main advantages eDNA surveys have over field surveying include the following.
- Time-Savings: A single visit during the correct eDNA survey season can verify the presence of a protected species such as the great crested newt. Similarly, conducting one eDNA survey can also confirm the absence of a species whereas four visits would be needed under a conventional survey to come to a negative conclusion. A field survey is more time-consuming and will involve methods such as egg searching, bottle trapping and torching.
- Greater Species Detection: The chance of detecting a species is generally better using eDNA methodology rather than traditional methods.
- Greater Accuracy: The eDNA approach is generally more accurate and error-free compared to conventional methods, therefore, providing better results.
- Disturbance-Free: With eDNA surveying, there is no need to disturb species in their natural habitats in order to determine their presence.
- Less Risk of Spreading Disease: eDNA samples are taken using sterile equipment, furthermore, there is no need to enter the water in order to take a sample. This reduces the chance of introducing alien or invasive species and the spread of diseases.
As this article has shown, eDNA surveys are a useful method of ascertaining the species present in a particular area without needing to collect or capture the wildlife itself.
At Greenlight, we are able to conduct a variety of surveys to suit your project requirements. Take a look round our website today or get in touch with us directly to find out more about what we can do for you.
